Patients with central visual field loss (CFL) have been reported to be at an increased risk of falling compared to those with normal vision,
9–13 supporting the view that the central area of the visual field is an important predictor of mobility performance.
14 Indeed, under difficult environmental conditions (such as walking across different surface terrain or under extreme light levels) compared to visual normals, patients with CFL adopt a more cautious gait strategy through walking slower and increasing head flexion to look down at more immediate areas of the ground.
15,16 Patients with CFL also adopt a flatter foot at contact with the ground when negotiating the different surface terrain.
15 When a population-based sample of older adults completed a mobility course (which consisted of walking through a cluttered environment with objects positioned throughout), CFL was associated with reduced walking speed and increased number of contacts with objects in the environment.
12 However, other research found that, when completing a mobility course, there was no difference in performance (measured using similar indices as Turano et al.
12) between patients with CFL and those with normal vision,
13,18 or when required to walk a pre-specified distance.
11 Wood et al.
19 also found that CFL had a minimal effect on gait when walking along level terrain, being associated only with the time both feet were in contact with the floor (double support time).
19 The effect that CFL has on mobility performance may be affected by task difficulty. Indeed patients with CFL have been shown to have poorer mobility performance when walking in increasingly difficult environments.
20 However, since Kuyk and Elliott did not include a control group,
20 it is difficult to ascertain whether the environment/terrain or visual impairment had influenced the results.